queue-5.1/drm-nouveau-add-kconfig-option-to-turn-off-nouveau-legacy-contexts.-v3.patch

   1 From b30a43ac7132cdda833ac4b13dd1ebd35ace14b7 Mon Sep 17 00:00:00 2001
   2 From: Dave Airlie <airlied@redhat.com>
   3 Date: Thu, 18 Apr 2019 16:45:15 +1000
   4 Subject: drm/nouveau: add kconfig option to turn off nouveau legacy contexts. (v3)
   5
   6 From: Dave Airlie <airlied@redhat.com>
   7
   8 commit b30a43ac7132cdda833ac4b13dd1ebd35ace14b7 upstream.
   9
  10 There was a nouveau DDX that relied on legacy context ioctls to work,
  11 but we fixed it years ago, give distros that have a modern DDX the
  12 option to break the uAPI and close the mess of holes that legacy
  13 context support is.
  14
  15 Full context of the story:
  16
  17 commit 0e975980d435d58df2d430d688b8c18778b42218
  18 Author: Peter Antoine <peter.antoine@intel.com>
  19 Date:   Tue Jun 23 08:18:49 2015 +0100
  20
  21     drm: Turn off Legacy Context Functions
  22
  23     The context functions are not used by the i915 driver and should not
  24     be used by modeset drivers. These driver functions contain several bugs
  25     and security holes. This change makes these functions optional can be
  26     turned on by a setting, they are turned off by default for modeset
  27     driver with the exception of the nouvea driver that may require them with
  28     an old version of libdrm.
  29
  30     The previous attempt was
  31
  32     commit 7c510133d93dd6f15ca040733ba7b2891ed61fd1
  33     Author: Daniel Vetter <daniel.vetter@ffwll.ch>
  34     Date:   Thu Aug 8 15:41:21 2013 +0200
  35
  36         drm: mark context support as a legacy subsystem
  37
  38     but this had to be reverted
  39
  40     commit c21eb21cb50d58e7cbdcb8b9e7ff68b85cfa5095
  41     Author: Dave Airlie <airlied@redhat.com>
  42     Date:   Fri Sep 20 08:32:59 2013 +1000
  43
  44         Revert "drm: mark context support as a legacy subsystem"
  45
  46     v2: remove returns from void function, and formatting (Daniel Vetter)
  47
  48     v3:
  49     - s/Nova/nouveau/ in the commit message, and add references to the
  50       previous attempts
  51     - drop the part touching the drm hw lock, that should be a separate
  52       patch.
  53
  54     Signed-off-by: Peter Antoine <peter.antoine@intel.com> (v2)
  55     Cc: Peter Antoine <peter.antoine@intel.com> (v2)
  56     Reviewed-by: Peter Antoine <peter.antoine@intel.com>
  57     Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
  58
  59 v2: move DRM_VM dependency into legacy config.
  60 v3: fix missing dep (kbuild robot)
  61
  62 Cc: stable@vger.kernel.org
  63 Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
  64 Signed-off-by: Dave Airlie <airlied@redhat.com>
  65 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
  66
  67 ---
  68  drivers/gpu/drm/nouveau/Kconfig       |   13 ++++++++++++-
  69  drivers/gpu/drm/nouveau/nouveau_drm.c |    7 +++++--
  70  2 files changed, 17 insertions(+), 3 deletions(-)
  71
  72 --- a/drivers/gpu/drm/nouveau/Kconfig
  73 +++ b/drivers/gpu/drm/nouveau/Kconfig
  74 @@ -17,10 +17,21 @@ config DRM_NOUVEAU
  75         select INPUT if ACPI && X86
  76         select THERMAL if ACPI && X86
  77         select ACPI_VIDEO if ACPI && X86
  78 -       select DRM_VM
  79         help
  80           Choose this option for open-source NVIDIA support.
  81
  82 +config NOUVEAU_LEGACY_CTX_SUPPORT
  83 +       bool "Nouveau legacy context support"
  84 +       depends on DRM_NOUVEAU
  85 +       select DRM_VM
  86 +       default y
  87 +       help
  88 +         There was a version of the nouveau DDX that relied on legacy
  89 +         ctx ioctls not erroring out. But that was back in time a long
  90 +         ways, so offer a way to disable it now. For uapi compat with
  91 +         old nouveau ddx this should be on by default, but modern distros
  92 +         should consider turning it off.
  93 +
  94  config NOUVEAU_PLATFORM_DRIVER
  95         bool "Nouveau (NVIDIA) SoC GPUs"
  96         depends on DRM_NOUVEAU && ARCH_TEGRA
  97 --- a/drivers/gpu/drm/nouveau/nouveau_drm.c
  98 +++ b/drivers/gpu/drm/nouveau/nouveau_drm.c
  99 @@ -1094,8 +1094,11 @@ nouveau_driver_fops = {
 100  static struct drm_driver
 101  driver_stub = {
 102         .driver_features =
 103 -               DRIVER_GEM | DRIVER_MODESET | DRIVER_PRIME | DRIVER_RENDER |
 104 -               DRIVER_KMS_LEGACY_CONTEXT,
 105 +               DRIVER_GEM | DRIVER_MODESET | DRIVER_PRIME | DRIVER_RENDER
 106 +#if defined(CONFIG_NOUVEAU_LEGACY_CTX_SUPPORT)
 107 +               | DRIVER_KMS_LEGACY_CONTEXT
 108 +#endif
 109 +               ,
 110
 111         .open = nouveau_drm_open,
 112         .postclose = nouveau_drm_postclose,